arjuna del tosohttp://arjuna.deltoso.net
Thu, 07 Apr 2011 21:30:54 +0000enhourly1http://wordpress.org/?v=3.3.2Usability of Everyday Things – Traffic Lightshttp://arjuna.deltoso.net/articles/usability-of-everyday-things-traffic-lights
http://arjuna.deltoso.net/articles/usability-of-everyday-things-traffic-lights#commentsSat, 30 Oct 2010 16:44:56 +0000Arjuna Del Tosohttp://arjuna.deltoso.net/?p=352In my way back home from the office sometimes I have to pass this traffic light, it’s at one end of Butt Bridge at the corner with Eden Quay, in Dublin (Ireland). The driver that arrives at the stop from the bridge can choose between three directions: left turn, right turn and straight. When the “system” is in “full green” status (Figure 1) there are no problems on understanding what to do, you can pick one of the three options (right, left, straight) and continue your journey.

Figure 1 - Green Light

But when the “system” is in “mixed colors mode” (Figure 2 and 3) I’m almost sure that more than one driver is left in a status of confusion.

Figure 2 - Green and Red, wtf?

Figure 3 - Detail

From the distance the big red light will catch your attention, both because red is the color of danger and also because we are used to recognise a pattern of three vertical lights on traffic lamps (with only one light on at any time). You will be tempted to reduce the speed and stop and this is what really happens quite often, with just a wait of a couple of minutes close to that cross is enough to realize it. Most of the time it takes some seconds for the car driver to understand that the green arrows on the left are eventually giving him/her the right to turn left or go straight.

On top of this, if you think that Dublin is a touristic destination for many Europeans that are used to drive their cars on the right side of the street and not on the left like in Ireland, it’s easy to imagine that just the task of driving on the “wrong side” will consume a lot of cognitive resources of a driver that will end in a frustrating experience. In my opinion, adding also a confusing street sign can lead to major problems (namely car accidents).

You don’t need a degree on usability to understand the big mistakes made designing this interaction: why using the sign “stop everybody”/red light to only stop cars turning right?, why using two more lights to override the main sign building thus a very strange and unusual configuration of the system?

]]>http://arjuna.deltoso.net/articles/usability-of-everyday-things-traffic-lights/feed2svn – Valid UTF-8 data followed by invalid UTF-8 sequencehttp://arjuna.deltoso.net/articles/subversion-messy-encoding-valid-utf-8-data-followed-by-invalid-utf-8-sequence
http://arjuna.deltoso.net/articles/subversion-messy-encoding-valid-utf-8-data-followed-by-invalid-utf-8-sequence#commentsTue, 29 Jun 2010 23:15:14 +0000Arjuna Del Tosohttp://arjuna.deltoso.net/?p=334This happened to me some time ago while working with a subversion repository in which there were some files created in Windows with a strange encoding. Issuing a simple svn status gave me this error message:

I searched for a solution but the best tip that I could find was to remove the files causing the error (seethis for example), but that wasn’t my case. I needed those files.

Discover the encoding of the filenames

So if you want to save your files and use them in subversion, you first need to discover the directory in which the files are stored. I just cd inside all the dirs checking if the error message was still relevant (may not be stylish but for me did worked). If you have a longer valid UTF-8 sequence than 4b you can try with:

echo "\x4b\x6f\x72\x5f" | xargs -0 printf

and it will give you the starting part of the corrupted filename (Kor_ in this example).

Once you have spotted the directory containing the files causing the error you need to discover the encoding of the filenames. Using the simple ls you should be able to spot strange files, for discovering the encoding of those files you can use the file command like this (if you have only one file you can try to substitute the * with the filename, but I don’t know if it works since I had all the files in that dir with the wrong encoding):

ls * | file -
/dev/stdin: ISO-8859 text

in normal circumstances (debian/ubuntu) the filename should be UTF-8 like this simple test shows

In my situation it happened that the filenames were latin1 but the content of the file was UTF-8, to be sure of this I used the isutf8 command (found in the moreutils package)

isutf8 *

that gives no output if everything is fine.

Convert the filenames to utf-8 encoding

At this point you need to convert the filenames to utf-8 encoding, this is easily achieved with convmv (on the man page you can read “converts filenames from one encoding to another” that is exactly what we need). The usage is simple:

]]>http://arjuna.deltoso.net/articles/subversion-messy-encoding-valid-utf-8-data-followed-by-invalid-utf-8-sequence/feed2Upgrade and Migrationhttp://arjuna.deltoso.net/articles/upgrade-and-migration
http://arjuna.deltoso.net/articles/upgrade-and-migration#commentsSat, 05 Jun 2010 12:53:20 +0000Arjuna Del Tosohttp://arjuna.deltoso.net/?p=314Today I’ve upgraded the version of wordpress to the last one, this site was still running on wp 2.6 due to the Gengo plugin (an old and discontinued multilingual plugin). From today I’m using wpml, let’s see if it works.

If you find that there are some errors (broken links, feeds not working, …) please drop me a message (use the contact page or leave a comment to this post).

Using WordPress as a CMS allowed to quickly build a full featured website for a small but dynamic company, WordPress also ensures that all the future needs and changes on the web presence of the company (i.e. blogs, newsletters, forums, …) will be easily deployed using it’s powerful plugin system.

]]>http://arjuna.deltoso.net/projects/inst-el-snc-hydroelectric-energy/feed0Google pushes advertisement on new designhttp://arjuna.deltoso.net/articles/google-pushes-advertisement-on-new-design
http://arjuna.deltoso.net/articles/google-pushes-advertisement-on-new-design#commentsTue, 01 Dec 2009 06:12:53 +0000Arjuna Del Tosohttp://arjuna.deltoso.net/?p=247Recently Google started testing a new massive redesign of the search engine interface (here instructions on how to activate the new design), Peter Van Dijck wrote a comprehensive article on the major changes (sidebar, input field, …). Here I would like to point out some details about the new design of the “Sponsored links” banner (Hey it’s where the G makes money).

First of all the old interface:

And now the new design:

And a detail of the main advertisement area:

Old Ads design

New Ads design

Some thoughts

As you can see, the new left sidebar forces the width of the light yellow box to a shorter version, the effect is that now it is more likely for an ad description text to be splitted in 2 lines, using more vertical space and thus having a higher probability to attract the eye of the user (compare the first and second ads on the two designs).

Without the horizontal bar (the one with “Web + Show options” button and the count of search results) the sponsor listing are much more closer to the input box, where the users is supposed to have the mouse pointer as he was just writing the search query text there (if he was already on a search result page).

The “Sponsored links” text now has a reduced font size (11px), it’s much less prominent and, with the use of a gray text color, it’s more difficult to spot it out at a first quick sight.

On the right ad box (the vertical one, without background color) there is an increased line height and white space between the sponsor listings. The law of proximity (from the gestalt principles) tells us that the single add will still be perceived as a unit, due to the bigger distance from one ad to the other, but now with more white space between the lines that perception is less strong, IMHO. Note also that the last ads, the less valuable, are more or less still under the fold.

Looking at the big screenshot, the map now occupies all the width of the central column; I think that this is done to discourage the user from scrolling and have him focusing on the sponsored listing. Such a strong visual block will for sure break the user’s “scan” of the page avoiding, or trying to avoid, him to “jump” under the map. For reference read the interesting research “The myth of the page fold: evidence from user testing” by cxpartners, where they found that “Stark, horizontal lines discourage scrolling”.

Last thing to note is that the first organic result is really close to the page fold, of course, it’s not paying

I personally believe that a lot of these changes are aimed to increase the CTR on the first 3 ads on google’s search results pages. What do you think?

Double disclaimer: if you have read this post up to here you may have guessed that I’m not so good in english, so report any error on the comments. More important, I’m not a interaction designer nor hci expert or wathever, these are only thought of a web programmer but I would like to know the opinion of the experts.

]]>http://arjuna.deltoso.net/articles/google-pushes-advertisement-on-new-design/feed0My configuration of xmonad window manager with xmobar and trayerhttp://arjuna.deltoso.net/articles/my-configuration-of-xmonad-window-manager-with-xmobar-and-trayer
http://arjuna.deltoso.net/articles/my-configuration-of-xmonad-window-manager-with-xmobar-and-trayer#commentsWed, 12 Aug 2009 22:06:07 +0000Arjuna Del Tosohttp://arjuna.deltoso.net/?p=242I’ll write here my configuration of xmonad in order to find it easily in the future. xmonad is a dynamically tiling X11 window manager that is written and configured in Haskell (http://xmonad.org/). I find xmonad really useful on systems with small screens and on laptops to avoid using the touchpad.

Software

How to install stuff

You’ll find more or less all the software needed on the repositories of the distribution of your choice (if you use ubuntu, like me, this should install the window manager apt-get install xmonad libghc6-xmonad-contrib-dev libghc6-xmonad-dev dwm-tools).

using gnome-settings-daemon (i.e. for multimedia keys) the use of feh for setting the background image is unnecessary.

Screenshots

A screenshot of the desktop without applications (only xmonad and trayer), the background image is the Ha’Penny Bridge, Dublin, by Steve:

now with some apps:

]]>http://arjuna.deltoso.net/articles/my-configuration-of-xmonad-window-manager-with-xmobar-and-trayer/feed16Ecofont, reduce ink consumption saving the green (and money)http://arjuna.deltoso.net/articles/ecofont-reduce-ink-consumption-saving-the-green-and-money
http://arjuna.deltoso.net/articles/ecofont-reduce-ink-consumption-saving-the-green-and-money#commentsSat, 14 Feb 2009 17:52:32 +0000Arjuna Del Tosohttp://arjuna.deltoso.net/?p=227Quick post only to point out a nice project of Spranq.nl called Ecofont. The aim of the project is to help people reducing the amount of ink used for printing, and save money too

]]>http://arjuna.deltoso.net/articles/ecofont-reduce-ink-consumption-saving-the-green-and-money/feed0Pligg Italian Language for version 9.9.5http://arjuna.deltoso.net/projects/pligg-italian-language-for-version-995
http://arjuna.deltoso.net/projects/pligg-italian-language-for-version-995#commentsWed, 28 Jan 2009 22:36:16 +0000Arjuna Del Tosohttp://arjuna.deltoso.net/?p=218Pligg is a MYODLWSMS (Make Your Own Digg Like Web Site Management System) written in PHP and it is used to make digg-like websites (this can’t surprise you, right?).

Since I wasn’t able to find a translation into Italian, I made one by myself starting from a previous version (I can’t remember where I found that translation, if you recognize it as yours drop a message and I will give credit).

]]>http://arjuna.deltoso.net/projects/the-fundamentals-of-graphic-design-wordpress-theme-2/feed10Automatic Oracle 10g Startup and Shutdown at Ubuntu Linux system boothttp://arjuna.deltoso.net/articles/automatic-oracle-10g-startup-and-shutdown-at-ubuntu-linux-system-boot
http://arjuna.deltoso.net/articles/automatic-oracle-10g-startup-and-shutdown-at-ubuntu-linux-system-boot#commentsWed, 15 Oct 2008 13:09:56 +0000Arjuna Del Tosohttp://arjuna.deltoso.net/?p=111Set the restart flag to “Y” in /etc/oratab, from something like this

dbname:/u01/app/oracle/product/10.2.0/db_1:N

to something like

dbname:/u01/app/oracle/product/10.2.0/db_1:Y

Copy&paste the boot script code that follows into /etc/init.d/dbora (the file dbora doesn’t exists, so create it) and modify the bold values to reflect your installation:

#!/bin/sh
# description: Oracle auto start-stop script.
#
# Set ORA_HOME to be equivalent to the $ORACLE_HOME
# from which you wish to execute dbstart and dbshut;
#
# Set ORA_OWNER to the user id of the owner of the
# Oracle database in ORA_HOME.
ORACLE_HOME=/u01/app/oracle/product/10.2.0/db_1
PATH=$PATH:$ORACLE_HOME/bin
export ORACLE_HOME PATH
ORA_HOME=/u01/app/oracle/product/10.2.0/db_1
ORA_OWNER=oracle
if [ ! -f $ORA_HOME/bin/dbstart ]
then
echo "Oracle startup: cannot start"
exit
fi
case "$1" in
'start')
# Start the Oracle databases:
# The following command assumes that the oracle login
# will not prompt the user for any values
su $ORA_OWNER -c "$ORA_HOME/bin/dbstart $ORA_HOME"
;;
'stop')
# Stop the Oracle databases:
# The following command assumes that the oracle login
# will not prompt the user for any values
su $ORA_OWNER -c "$ORA_HOME/bin/dbshut $ORA_HOME"
;;
esac

Assign proper script privileges:

chmod 750 /etc/init.d/dbora

Create the symbolic links related to boot runlevels [since I'm a long-time-Slackware-user and pretty new to Ubuntu, I'm not well versed about Ubuntu boot system so feel free to correct me (the comments are at the end of the post)]:

Release 2 bug: inside /u01/app/oracle/product/10.2.0/db_1/bin/dbstart there is a bug that will prevent the listener to start (Failed to auto-start Oracle Net Listener using /ade/vikrkuma_new/oracle/bin/tnslsnr); to solve change line 78 from